This invention relates to a concrete form for forming a concrete structure and particularly to a modular concrete form unit including a form plate backed by transverse channel pieces detachably provided along transverse sides of the form plate and trussed backing members longitudinally extending and detachably connected to the channel pieces.
It is now a common practice to assemble modular form panels to a large form board which can be stripped entirely from a formed concrete structure and which can be used repeatedly to form similar concrete structures without the need to disemble and reassemble the form board. Generally, such form panels include a plate member and reinforcement members connected to the back of the plate. U.S. Pat. No. 2,544,297 discloses a foldable form including a steel panel and a plurality of longitudinal and transverse reinforcement struts which are connected to the panel for backing purposes by a time-consuming welding process. Well known steel-ply panels which are manufactured by Symon Corporation include rectangular plywood panels arranged in edge-to-edge contiguity, and a rectangular reinforcing frame is used to back the plywood panels. Usually, in conventional form boards, thick panels are utilized to increase the strength of the form panel or minimize the deflection of the panel, thereby increasing the weight of the form assembly. Furthermore, the backing members to reinforce conventional form panels are usually welded to the form panels so that the variable dimension of form panels is an integral multiple of the dimension of standard form panels, thereby limiting the variation in dimension of the form panels.